(9090) Chirotenmondai Main-belt Asteroid
Discovered on 28 October 1995 by Endate, K., Watanabe, K. at Kitami.
Named for Chiro Astronomical Observatory (Chiro tenmondai) in Western Australia. Founded in 1995 by the joint efforts of Australian and Japanese amateur astronomers, it is also operated by the two groups. It is a considered a sister observatory to the Japanese amateurs' Shirakawa Observatory, the two sites being at approximately at the same latitude in opposite hemispheres. Name proposed by the discoverers following a suggestion by L. Taylor and T. Sato.Naming citation (19981208/MPCPages.arc), IAU / Minor Planet Center, via NASA/JPL
Where Chirotenmondai is today
Seen from above the solar system on 2026-10-14: Chirotenmondai is 2.82 au from the Sun and 2.38 au from Earth. Computed from JPL's orbital elements.
Facts
| Number | 9090 |
| Provisional designation | 1995 UW8 |
| Orbit class | Main-belt Asteroid |
| Diameter | 17.6 km (#2,560 largest of 17,440 named asteroids with a measured size) |
| Albedo | 0.0420 |
| Rotation period | 5.65 hours |
| Absolute magnitude (H) | 12.81 |
| Orbital period | 4.56 years |
| Semi-major axis | 2.75 au |
| Perihelion – aphelion | 2.49 – 3.01 au |
| Eccentricity | 0.0950 |
| Inclination | 13.7° |
| Closest distance between its orbit and Earth's (MOID) | 1.50 au |
Data: NASA/JPL Small-Body Database and the IAU Minor Planet Center.
Also discovered on 28 October 1995
- (7494) Xiwanggongcheng
- (9215) Taiyonoto
- (13163) Koyamachuya
- (16719) Mizokami
- (17617) Takimotoikuo
- (22416) Tanimotoyoshi